The French did considerable work in the army, as well as the navy, after the disasters of the Seven Years War. One of the things they worked on was infantry tactics to find a new system that would work against the Prussians.
The work done at the Camp of Vaussieux and other places in the 1770s was crucial to the tactical improvement of the French army and greatly benefitted the Grande Armee in later years.
Marshal de Broglie, prompted by Mesnil-Durands tactical ideas on the ordre profond, began a series of tactical experiments and maneuvers to test Mesnil-Durand’s ideas against the usual French practice of l’ordre mince. The first maneuver was carried out at Metz by the Metz garrison, four battalions of infantry in 1775. The results were ‘mixed’ but it was proposed that Mesnil-Durand’s ideas were sufficiently interesting to undergo further testing and experimentation.
The next series of maneuvers were undertaken at Vaussieux in Normandy between Bayeux and Coucelles-sur-Mer after the entry in the War of the Revolution against England. There were 44 battalions of infantry, 6 dragoon regiments and a considerable artillery train. Marshal de Broglie was placed in command with the Marquis de Lambert as marechal-general des logis. Mesnil-Durand was appointed as one of his assistants. The elder de Guibert as assigned as major-general (chief of staff), with his son and the younger de Broglie as assistants.
The other senior officers assigned to the maneuvers in Normandy were Lieutenant Generals Luckner, Gribeauval, Chabot and De Vault; Marechaux de Camp Rochambeau, Conflans, Wimpfen, La Tour du Pin, and Durfurt. A total of nine lieutenant generals and eighteen marechaux de camp were assigned to the maneuvers as well as six brigadiers.
Wimpfen would write the only period account of the maneuvers, Relation de ce qui est passe au camp de Vaussieux. He and de Broglie would heatedly disagree on the outcome of the maneuvers, each with his own viewpoint on what was accomplished.
Eight different evolutions of the maneuvers were conducted between 9 September and 28 September 1778 and the bottom line was to see if Mesnil-Durand’s heavy columns were better than units in line for offensive infantry maneuvers and tactics.
September 9th-the 1st maneuver; September 11th-the 1st maneuver is repeated because of errors on 9 September; September 12th-the 2d maneuver; September 14th-the 3d maneuver; September 15th-the 4th maneuver; September 17th-the 5th maneuver; September 21st-the 6th maneuver; September 24th-the 7th maneuver; September 28th-the 8th maneuver which completed the exercise.
De Broglie supported Mesnil-Durand’s idea of the ordre profond, and Wimpfen was against it. The other general officers formed their own opinions, but the bottom line was that Mesnil-Durand’s large columns were too large and unwieldy and therefore impractical. De Broglie disagreed and believed that the maneuvers proved the viability of the large columns. That was a minority opinion.
What was proven, though, is that troops in formation supported by large number of regular infantry deployed as a fire support element in the attack did work.
While de Broglie and Wimpfen disagreed tactically, and can be considered at the extremes of the argument, two French general officers adopted a ‘middle ground’ in the argument. The Marquid de Castries commanded the Camp at Parame in 1778 and conducted maneuvers on the model of Vaussieux but he had fewer troops than de Broglie fielded. De Castries was a proponent of the ordre profond and his maneuvers were conducted the maneuvers with battalion colums, which were smaller, easy to manuever and deploy and were again supported by large numbers of skirmishers. He left a written record of the maneuvers.
The Comte de Puysegur, another supporter of the ordre profond, agreed with de Castries and endorsed the idea of battalion columns covered by skirmishers. Both de Castries and de Puysegur rejected Mesnil-Durand’s heavy columns instead preferring smaller battalion columns and this idea is what was employed once the French again went to war.
The doctrinal product of the maneuvers would eventually be the Reglement of 1791, even though other infantry reglements were produced, the culmination would be that of 1791 which was the infantry regulation that was used by the French from 1792-1815.
It should be noted that the 1791 Reglement did not mention the employment of skirmishers in large numbers to be used as the fire support element, along with battalion columns, in the attack. That would come when war came and would become part of the French tactical system.
In The Military Experience in the Age of Reason on page 279 reads:
‘Mesnil-Durand, Joly de Maizeroy and Saxe were among the authorities who called for a closer working of regular and skirmishing tactics.’
So, even though Mesnil-Durand’s heavy columns were judged a failure, the idea of coordinating regular troops in formation with regular troops deployed as skirmishers in large numbers was being thought of at least as early as Marshal de Saxe and would come to fruition when the French army went to war in 1792.